"People have long reported that it is harder to get to sleep and remain asleep when the moon is full, and even after a seemingly good night's rest, there can be a faint sluggishness -- a sort of full-moon hangover -- that is not present on other days. If you're sleeping on the prairie or in a settler's cabin with no shades, the simple presence of moonlight is an inescapable explanation. But long after humans moved indoors into fully curtained and climate-controlled homes, the phenomenon has remained. What's never been clear is whether it's the real deal -- if the moon really does mess with us -- or if it's some combination of imagination and selective reporting, with people who believe in lunar cycles seeing patterns where none exist. Now, a report in the journal Current Biology suggests that the believers have been right all along."

This sample is in pretty good shape, but a few changes here and there would help to bring the Fog score below 12. The first sentence weighs in at a whopping 46 words, and another sentence later in the excerpt is 40 words. It would seem that sentence length is the problem here. Let's see what we can do:

"People have long reported that it is harder to get to sleep and remain asleep when the moon is full. Even after a seemingly good night's rest, there can be a faint sluggishness -- a sort of full-moon hangover -- that is not present on other days. If you're sleeping on the prairie or in a settler's cabin with no shades, the moonlight is an obvious culprit. But long after humans moved indoors into fully curtained and climate-controlled homes, the phenomenon has remained. What's never been clear is whether it's the real deal. Does the moon really mess with us? Is it some combination of imagination and selective reporting, with people who believe in lunar cycles seeing patterns where none exist? Now, a report in the journal Current Biology suggests that the believers were right all along."

Our edits here were fairly light. Much of the work involved splitting up longer sentences. (We made 8 sentences where there were just 5.) We also reframed some divided sentences as questions for optimal flow. We left most of the longer words intact; the percentage thereof is quite small for a sample of this size.